1. Field of the Invention
The disclosures herein generally relate to controlling establishing a session between communication terminals to transmit the contents data in a communication system that includes multiple relay management devices to manage relaying the contents data transmitted from the communication terminals.
2. Description of the Related Art
In recent years, demand for reducing the cost and time spent for business trips has risen, and a communication system has become popular that is for calls and conferences in which communication is made via a communication network such as the Internet, dedicated lines, and the like. In such a communication system, once a communication is started between communication terminals, contents data such as image data and sound data is transmitted and received so that participants can communicate with each other.
Also, in a communication system for a video conference, other than communication terminals, MCUs (Multipoint Control Units) and a management device to manage the MCUs are provided. An MCU relays contents data, such as image data and sound data, among communication terminals at multiple sites by receiving contents data transmitted from a communication terminal, and transmitting the data to one or more other communication terminals under management by the management device.